The Free Dictionary identifies "Merrimac" as "an ironclad vessel built by the Confederate forces in the hope of breaking the blockade imposed by the North". This gives me the impression that perhaps the heavy equipment is moving in to clear the density.
Source: Gaia Portal
Merrimacs enter, where calcifieds have failed.
Steadfastness of the Higher Light dissolve all blocks.
Mortifications are annulled.
Uplevellings are embraced.
Necessities are only of the Light.